1. Field of the Invention
The present invention relates to natural language spoken dialog systems, and more specifically to discovering changes in natural language used by callers of human/computer interactive systems.
2. Introduction
Modern computers can understand natural language at a useful level. For example, existing natural language spoken dialog systems receive, process, and transcribe a caller's telephone audio signal automatically. Semantically loaded words allow a machine learning algorithm to build a classifier that performs well on a restricted domain. Yet as time passes, customer needs can evolve beyond the situations that arose within the training data. As a result, the automated classifier may not perform acceptably on novel requests. Recognizing such situations and retraining the classifier can help to maintain user satisfaction and prevent financial losses.